The present invention relates to an ink fountain apparatus which stores ink to be supplied to a plate surface in a printing press.
As shown in Japanese Utility Model Laid-Open No. 2-15352, a conventional ink fountain apparatus for a printing press has an ink fountain including a rotatably supported ink fountain roller, a bottom plate arranged at a position close to the ink fountain roller, and a pair of ink dams arranged in a direction perpendicular to the bottom plate and opposing each other in the widthwise direction of the bottom plate. The ink dams are moved and adjusted in the vertical direction and back-and-forth direction, and are fixed after their distal end faces are aligned with the outer surface of the ink fountain roller.
In the conventional ink fountain apparatus for the printing press, as the total length in the axial direction of the ink fountain roller is larger than the total length in the axial direction of an ink ducting roller, noncontact portions which do not come into contact with the ink ducting roller are present on the two end portions of the ink fountain roller. Ink on the noncontact portions is not transferred to the ink ducting roller but remains on the ink fountain roller as excessive ink. When the excessive ink drops on a printing product, a printing trouble occurs.
As the front end of each ink dam must form an arc having the same radius of curvature as that of the outer surface of the ink fountain roller, machining of the ink dam requires high accuracy. A gap, although small, tends to be formed between the front end of the ink dam and the outer surface of the ink fountain roller. As the ink fountain roller rotates over a long period of time, the front end of the ink dam wears to gradually form a gap between the front end of the ink dam and the outer surface of the ink fountain roller. Consequently, ink leaks through the gap, also causing a printing trouble.